TAMPA — As Isaac barrels toward New Orleans seven years after Katrina, Mitt Romney’s campaign advisers are quickly rewriting the script for the convention that they had spent months carefully choreographing.

Advisers had planned nearly every image — from the number of screens on stage, to biographical video, to old family photos — with the hope that voters would see a more expansive view of the Republican presidential nominee. But now, they may be confronted with far different images: a festive party in Tampa, with delegates applauding and wearing funny hats, while residents along the Gulf Coast deal with a natural disaster.

Romney campaign advisers Monday were contemplating a variety of scenarios, including the possibility of canceling the convention, but emphasized that nothing was certain, with convention plans now as unpredictable as the weather.

“We have to be nimble, which we will be,” Reince Priebus, the chairman of the Republican Party, told reporters Monday afternoon. “But right now we see us moving forward as planned.”

Forecasts on Monday indicated that the eye of the storm would strike New Orleans around 2 p.m. on Wednesday, about five hours before Republicans convene for a series of speeches that culminate with an address by vice presidential nominee Paul Ryan.

It means there quite literally could be a split screen, with television network coverage alternating between the hurricane’s destruction and the Republican celebration.

President Obama on Monday declared a state of emergency in Louisiana, authorizing the Federal Emergency Management Agency to begin preparing for disaster relief. Residents along the coasts of Louisiana, Mississippi, and Alabama were beginning to evacuate.

Governors from coastal states canceled their appearances at the convention to coordinate response efforts. Governor Bobby Jindal of Louisiana, who was scheduled to address the convention Thursday, canceled his speech. News media began moving some of their top correspondents from Tampa to New Orleans, planning to cover the brewing storm instead of the Republican gathering.

The storm was also being closely monitored by the Obama campaign, although the president was planning to continue Tuesday with his two-day, three-city college tour through battleground states Iowa, Colorado, and Virginia.

The storm had already forced convention planners to cancel many activities on Monday, and cram speakers who were scheduled over four days into three instead.

The changes in logistics have been handled primarily by Russ Schriefer, a top Romney adviser who has been stationed in a room at the Tampa Marriott Waterside Hotel & Marina. The campaign has been getting regular updates on the weather, and has been coordinating closely with the Republican National Committee.

“We expect no change over the next three days,” Schriefer told reporters on a Monday night conference call. “We are in full speed, planning ahead with our Tuesday, Wednesday, Thursday schedule.”

He said the weather was being monitored closely, and there had been early discussions about using the convention to coordinate relief efforts for those affected by the hurricane. But he said there would be little difference in tone as Republicans seek to criticize Obama’s policies.

“I don’t think it is really going to change much of what we’re going to do,” Schriefer said. “I think we’re going to continue to talk about the differences between Governor Romney and President Obama.”

When asked earlier in the day whether the convention would be canceled, Beth Myers, another top Romney adviser, told WBZ Radio, “Time will tell.”

But illustrating the types of internal discussions the Romney campaign is having, one adviser was already contemplating what would happen if the convention were canceled. The adviser, who wished not to be identified discussing internal deliberations, said there could even be consideration for asking the television networks for a prime-time speaking opportunity for Romney if the convention were not completed.

The weather left Romney advisers with no definite answers about the course the week would take. “Look, we’re worried about the poor people at the landfall-end of the weather, you’re certainly worried,” said John Sununu, the former New Hampshire governor and a campaign adviser. “You tell me exactly what the situation is going to be and guarantee it, and I’ll give you an answer. But you can’t. There’s a thousand possibilities and I can’t give a thousand answers.”

Romney on Monday left his vacation home in Wolfeboro, N.H., where he had been preparing his convention speech, including a practice round in the auditorium of nearby Brewster Academy, and was planning to spend the night in Belmont. Mitt and Ann Romney were planning to arrive in Florida in time for her speech on Tuesday. Mitt Romney is slated to travel to Indiana on Wednesday to address an American Legion meeting.

“Our thoughts are with the people that are in the storm’s path and hope that they’re spared any major destruction,” Romney told reporters Monday. Asked whether he was considering canceling the convention, he said, “Got a great convention ahead.”

The convention had a low-key mood on Monday, with many of the activities on the floor canceled in anticipation of the storm. But the weather was less severe than expected. By midday the sun came out, and a charity golf tournament, Birdies for the Brave, still took place. Actor Jon Voight wandered around the convention area.

At 2 p.m., a smattering of delegates filed into the convention hall, and the meeting was formally gaveled into session. It lasted about 10 minutes, all of it mostly a formality to get the convention underway. A brief video about Romney was shown and a prayer was said, including for those in the path of the storm.

Republican Party leaders sought to project a sense of calm, but there was also an acute awareness that one of their major chances to project their vision for the country was being diluted.

“There’s a practical concern that if there’s a dangerous event in the Gulf Coast over the next 48 hours that people might turn more attention to that as opposed to hearing Paul Ryan or somebody else talking about our vision for America,” Virginia Governor Bob McDonnell said in an interview. “But everybody knows, this is something you just can’t control. You’ve got to roll with the punches.”

The storm is also a vivid reminder of Hurricane Katrina, which struck almost seven years ago to the day, and President George W. Bush’s much-criticized handling of the emergency response.

Republicans four years ago canceled the first day of their convention — which was being held in Minneapolis — because Hurricane Gustav was about to hit the Gulf Coast.

“I would not want to be the consultant advising the Republicans on how to have a celebration of Romney and their party while there is a split screen showing people suffering from a big storm,” said Scott McLean, professor of political science at Quinnipiac University. “They’re in a tough spot. They really do need to figure out how to adjust the tone of the celebration aspect.’’

Already, there appeared to be some off-key comments that Democrats were eager to point out. At a rally on Sunday, a US Senate candidate in Texas made a joke about the storm, saying Republicans should be happy about its arrival because it caused Vice President Joe Biden to cancel his trip to Tampa.

“We can be thankful for Hurricane Isaac,” Ted Cruz said at a Faith and Freedom Coalition rally. ”If nothing else it kept Joe Biden away.”

Representative Darrell Issa, a California Republican, said on Monday that he was “fine” with the storm hitting the Gulf Coast.

“I think what you have to remember is Republicans are going to take Washington by storm on Jan. 20 of next year. So if this is the first storm of Republicans taking control of our country again, making America competitive again, I’m fine with that,” Issa said at a California delegation breakfast, according to Politico. “I don’t care if we get blown in by a hurricane or a tornado; ultimately there’s going to be an earthquake in Washington next January.”

Michael Robinson, executive vice president of Levick, a crisis communications firm that has advised on the gulf oil spill, said there were risks for Republicans in how they handle the next few days.

But there also could be opportunities for Romney, who has been criticized as cold and aloof, to show a more emotional side.

“Just imagine for a minute the impact of people saying, ‘Hey, I didn’t realize that Mitt Romney was in there,’ ” said Robinson, a former Bush administration spokesman. “It is entirely possible that Romney has this Rudy Giuliani moment.”

Matt Viser can be reached at maviser@globe.com. Glen Johnson can be reached at johnson@globe.com. Brian C. Mooney of the Globe staff contributed to this report.